Incidence Of Milk Fever Research Articles

Milk fever prevention update and vitamin D3 toxicity

Discussing problems of milk fever with practicing veterinarians today reveals that in some herds there are occasionally epidemics that occur for a variable period of time in some herds. The overall incidence in the U.S. is apparently down from the 8-9% of the 1960’s to about 6-7%. However, sales of milk fever treatments may be rather stable. This may also mean that the average milk fever cow may get 2 bottles per treatment.
 Today, in the large herds, where caloric and calcium intake are very closely regulated to minimize overfeeding of energy and calcium, the herd incidence of milk fever may be below 1%. The major question for the medium size farm is whether or not it is worthwhile to prevent milk fever if the management upset is too great. This is a real problem for dairymen on all legume forages.

Genetic Interrelationships of Parturition Problems and Production

Data were 5091 calvings from 3904 cows for milk fever, retained placenta, mastitis within 48-h postpartum, calving difficulty, and 48-h calf livability collected from 27 large California dairies analyzed for genetic interrelationships among parturition problems. Heritability of each trait was small; however, retained placenta had large positive genetic correlations with milk fever (.34) and mastitis (.33). Adding difficulty-mortality classes to models to study genetic relationships of parturition problems had little effect on estimates but did influence incidence of parturition problems.With calving difficulty, incidence of milk fever increased by 4.9% and retained placenta by 5.3%. With calf mortality, milk fever increased by 4.4% and retained placenta by 13%. A combination of difficulty and mortality was related to a 9.6% increase of milk fever and a 20.2% increase of retained placenta.Genetic correlations of all problems with mature equivalent milk indicated that selection for increased production would be accompanied by lower incidence of retained placenta, 48-h mastitis, and milk fever. Genetic correlations of retained placenta with milk fever and 48-h mastitis were positive. Selection for increased milk yield should not increase incidence of parturition problems, and prescreening of bulls on parturition performance of daughters would be feasible.

Magnesium and milk fever.

There is clinical, experimental and theoretical evidence for a connection between the occurrence of subclinical hypomagnesaemia and the incidence of milk fever. Clinically, pregnant dry cows in dairy herds with a high incidence of milk fever have often been observed to have subnormal blood magnesium concentrations. Experimentally, it has recently been shown that subclinical hypomagnesaemia reduced the ability of cows to mobilise calcium in response to hypocalcaemia; a response which is essential if cows are to avoid milk fever. And theoretically there are several points in the biochemical pathways for calcium where a need for magnesium has been demonstrated in laboratory rodents. These connections between subclinical hypomagnesaemia and milk fever are explored and their consequences for the prevention of milk fever are considered.

The effect of 1 alpha-hydroxycholecalciferol on the concentrations of calcium, magnesium and inorganic phosphate in the plasma of parturient cows.

135 Cows which were expected to produce a second or subsequent calf within 4--11 received an intramuscular injection of 500 micrograms 1 alpha-hydroxycholecalciferol (1 alpha-OHD3). In those animals in which the interval between injection and calving was at least 7 d there was, at 7 d after injection of 1 alpha-OHD3, a significant increase (P less than 0.001) in the blood plasma concentrations of Ca and Pi and a significant reduction (P less than 0.05) in that of Mg, compared with those in control animals. Within 24 h of calving there was a significant increase (P less than 0.001) in the concentration of Pi but no change in Ca or Mg compared with pre-injection levels, whilst the control animals showed a significant fall (P less than 0.001) in the concentration of Ca and a rise in those of Pi (P less than 0.001) and Mg (P less than 0.05). There was a significant reduction (P less than 0.001) in the number of animals with hypocalcaemia (defined as a plasma Ca concentration less than 1.9 mmol/l) in all animals injected with 1 alpha-OHD3; this reduction was particularly marked when the interval between injection and calving was between 1 and 8 d. The previously reported reduction in the incidence of clinical milk fever is considered to be a consequence of the effect of 1 alpha-OHD3 on the concentration of Ca in plasma.

A field trial of 1alpha-hydroxycholecalciferol (1alpha-OH D3) in the prevention of milk fever.

The efficacy of 1alpha-OH cholecalciferol for the prevention of milk fever has been tested in a controlled field trial using 597 cows on 19 farms all of which had previously had a high incidence of milk fever. Of 293 cows receiving 1alpha-OH cholecalciferol 34 had milk fever and of 304 control cows 51 had milk fever. Although there was an apparent efficacy of 31 per cent the difference in incidence was not statistically significant. There was no effect if 1alpha-OH cholecalciferol was administered less than 24 hours before the cows succumbed to milk fever. However, if 1alpha-OH cholecalciferol was administered more than 24 hours and less than one week before the occurrence of milk fever the efficacy increased to 61 per cent and the effect was highly significant.

Milk Fever in Dairy Cows. VIII. Effect of Injected Vitamin D3 and Calcium and Phosphorus Intake on Incidence

In a field trial, effects of prepartal intermuscular injection of 10million units of vitamin D3 on incidence of milk fever were examined both in relation to intake of calcium and phosphorus during the dry period and previous history of milk fever. Based upon intake of calcium and phosphorus cooperating herds were grouped as feeding: 1) >.53% of the total ration dry matter as calcium and >.28% as phosphorus; 2) <.47% as calcium and >.28% as phosphorus; 3) >.47% to <.53% as calcium and >.22% to <.28% as phosphorus. Injections of vitamin D3 given approximately 1 wk prepartum reduced incidence of milk fever in cows with previous history of milk fever in all three groups but had no effect in cows with no previous milk fever. Incidence of milk fever was lower in group 3 than for cows of groups 1 and 2 with previous milk fever and than for cows of group 1 with no previous history. The results indicate that careful control of calcium and phosphorus intake during the dry period at .5% calcium and .25% phosphorus of the dry matter of the total ration will limit milk fever incidence to about 10%. Injections of vitamin D3 as described will reduce incidence of milk fever further in cows with previous milk fever but not in cows with no previous milk fever.

Effect of Prepartal Hormone Administration on Feed Intake and Mineral Metabolism of Cows

Subcutaneous administration of progesterone (.25 mg/kg body weight per day) to mature cows from 14 days before projected parturition until parturition increased feed intake over control cows. Incidence of milk fever and plasma calcium, phosphorus, magnesium, and hydroxyproline were not significantly different between treated and control cows. Subcutaneous administration of estradiol-17β (.05 mg/kg body weight per day) or oral administration of melengestrol acetate (1 mg/day) from 7 days before projected parturition date until parturition decreased feed intake over control cows. Milk fever incidence and absorption of calcium, phosphorus, and magnesium were not significantly different between treatment groups. Plasma calcium was not significantly different between treatment groups durng either the prepartum or postpartal periods but tended to be higher postpartum in cows treated with estrogen.

An Apparent Reduction in the Incidence of Milk Fever Achieved by Regulation of the Dietary Intake of Calcium and Phosphorus

Mature Friesian cows were given silage plus either an alkaline or an acidic concentrate mix during the last 28 days of pregnancy in two experiments. There were no significant differences in plasma calcium, phosphorus or magnesium concentrations before parturition but the blood ionised calcium and plasma chloride concentrations were significantly increased, together with a lower blood pH and acid-base excess in the cows on the acid diet. The mean 1,25-dihydroxyvitamin D concentrations tended to increase before parturition in the cows on the acid diet compared with the alkali diet in experiment 1 and were significantly higher in experiment 2. At parturition, the acid-fed cows had higher mean plasma calcium concentrations and significantly more of them had values >2·0 mmol litre−1 than the alkali-fed groups, and the plasma 1,25-dihydroxyvitamin D and parathyroid hormone concentrations were related to these different plasma calcium concentrations. The acidic diets therefore appeared to prevent the onset of hypocalcaemia at parturition by increasing the plasma 1,25-dihydroxyvitamin D concentration before parturition.

Clinical and biochemical responses to the treatment of milk fever.

One hundred and eighty-six cases of milk fever in 80 herds spread over five counties were used to compare treatment with 8g calcium plus 500 mg magnesium in aspartate with the conventional 12-36g calcium as borogluconate. The data obtained from both the herds and their individual cases show that the treatments gave broadly similar results, and a single intravenous treatment cured 74-7 per cent of cases. It appeared that milk fever was not likely to recur with each succeeding parturition. No breed susceptibility was recognised. No correlation was found between the severity of the clinical signs and the inorganic phosphate concentrations. An incidence of milk fever of 8-79 per cent was recorded.

Initiation of Parturition in Dairy Cows with Dexamethasone. I. Cow Response and Performance1,2,3

Parturition was initiated in 25 of 29 Holstein cows given dexamethasone (4.4mg/100kg body weight) intramuscularly at day 273 of gestation. Parturition occurred at 45.1±11.1h after injection. The 29 control cows which were compared to 29 induced cows had an average gestation length of 280 days. Calving difficulty was greater while birth weight of calves was 3.0kg less for the induced cows compared to control cows. Severity of udder edema did not differ between groups. Average daily milk production for the first 9 wk of lactation was 24.8kg and 27.8kg for the induced and control groups. Differences in milk fat or fat-corrected milk were nil. Changes in body weight were similar for all cows. Incidence of retained placental membranes was 76 and 10% for induced and control cows. Average days to first heat, days to first service, days to conception, and services per conception for induced cows were 58.4, 79.9, 117.8, and 2.0 and for control cows were 58.6, 82.3, 105.5, and 1.8. The incidence of milk fever in cows with no previous history was 24 and 10% for induced and control cows. Results of California Mastitis Tests taken at 15 and 30 days post calving were similar. Fat, protein, total solids, and gamma globulin content of the colostrum did not differ between groups.

Mineral Nutrition, Calcium, Phosphorus, Magnesium, and Potassium Interrelationships1,2

There are over 70 known mineral interrelationships in which an additional dietary quantity of one mineral element will influence absorption or utilization of another mineral element. As the animal ages, the readiness of availability of stored mineral elements in the bone decreases. Animals do adapt to reduced dietary intake of minerals as shown for Ca by reducing fecal excretion and increasing absorption. The adaptation, however, may occur simultaneously with a reduction in milk production. Borderline deficiency or insufficiency of mineral elements leads to decreased feed intake and milk production. Diagnosis is extremely difficult. A large proportion of commonly used feedstuffs are below the required concentration of at least one mineral element for high milk production. Since few dairymen know how much of each mineral element is in their cows’ diet, milk production may unwittingly suffer from mineral deficiency, insufficiency, or toxicity. Excessive rather than too little dietary Ca during the dry period prior to calving is likely contributing to an increased incidence of milk fever. Basically, blood P must be maintained by absorption from the gut as there is no known specific mechanism for bone resorption. Therefore, it is important always to include adequate P in the diet. Too little Mg may be causing problems that are not well understood, or widely appreciated. Supplemental K is probably indicated on some high concentrate feeding programs. All mineral elements should be considered in ration formulation for high performance and a reduction in mineral nutrition anomalies.

Prepartum Grain Feeding Effects on Milk Production, Mammary Edema, and Incidence of Diseases

The influences of feeding grain before calving on milk production, mammary edema, and disease were determined in 98 heifers and 50 cows. Half of them were fed grain to appetite starting 21 days prepartum while the others received no grain until after calving. All animals received grain to appetite after calving through 45 days postpartum. The 220kg of grain fed per heifer before calving resulted in an extra 54kg of milk during the 45-day milking period and the 295kg of grain per cow resulted in an increase of 36kg of milk. Thus, the practice was uneconomical in this trial where the animals entered late pregnancy in good condition. Prepartum grain feeding also increased the severity of edema in heifers, but not in cows. Although a number of diseases such as metritis, retained placenta, and indigestion were not significantly affected by prepartum grain feeding, the incidence of milk fever was significantly increased and the incidence of mastitis was increased twofold in heifers and somewhat less in cows.

Parturient Paresis Related to Dietary Phosphorus

A lack of available dietary phosphorus during lactation is a predisposing factor in the cause of milk fever.A herd of Jersey cows having a high incidence (74%) of milk fever, were subjected to an experimental ration during lactation. The ration concentrate contained 5% monosodium phosphate but no calcium supplement. This was sufficient to near-balance the calcium-to-phosphorus intake. There was no incidence of milk fever in the experimental animals during the following parturition, when they had received the experimental ration over a given period while lactating (189 days before calving or approximately 130 days during the latter part of their lactation). Control animals fed the regular ration continued to have a high incidence of milk fever.When the feeding of the experimental ration was discontinued, the first incidence of milk fever occurred in 232 days, or after the experimental cows had gone through a lactation without the phosphorus supplement.The usual large amount of calcium and limited amount of phosphorus in dairy rations is, undoubtedly, one of the main reasons that sufficient dietary phosphorus is not available to heavily lactating cows, although the level of phosphorus in the ration might meet recommended levels. The usual addition of calcium supplements to dairy concentrates is certainly not justified under most feeding conditions.

Studies of Milk Fever in Dairy Cows. VI. Effect of Three Prepartal Dosage Levels of Vitamin D on Milk Fever Incidence

Summary A field study involving 164 parturitions in Jersey cows, all with previous milk fever histories, in 26 Ohio herds was conducted to obtain further information on how much vitamin D must be fed prepartal to provide maximum protection against milk fever. The assigned vitamin D dosage, 15, 20, or 30million units/day, was fed on a twice-a-day basis beginning approximately five days before the expected calving date and for one feed after parturition. If seven days feeding were completed before parturition, vitamin D feeding was terminated. On-schedule cows were those that received at least three days of vitamin D feeding and calved within one day after termination of vitamin D feeding. In all, there were 113 in the on-schedule group. In the off-schedule group ten cows calved too early and 41 calved too late. Three vitamin D concentrates were used: Viosterol (capsules), Type 142F Irradiated Dry Yeast, and Super Drex 3000. The average per cent protection for the three dosages, based on 64% milk fever expectancy in Jersey cows with previous milk fever histories, was 67.1% for the 15million unit level, 82.0% at the 20million unit level, and 79.2% at the 30million unit level. No statistically significant differences were found in milk fever incidence or per cent protection among the three vitamin D dosage levels. Vitamin D was fed for an average of 5.6 days (11.2 feedings) prepartal, including the day of parturition in the on-schedule group. Because the 15million unit/day dosage level resulted in a lower average protection than the two other dosages, it was considered unwise to recommend less than 20million units per day, until more numbers can be studied. There was no evidence, however, that 30million units per day would be more effective than 20million units per day. All three vitamin D concentrates used appeared to be equally effective when consumed. Certain cows did not accept irradiated yeast readily. The viosterol capsules had the advantages gained from forced feeding and Super Drex 3000 offered no palatability problem. Evidence obtained indicated that protection increased for the first three days of vitamin D feeding, remained at a high level after the third through the seventh day, and dropped precipitously after one day had elapsed following cessation of vitamin D feeding.

URINARY CALCIUM EXCRETION AND BLOOD CALCIUM LEVELS IN THE BOVINE NEAR THE TIME OF PARTURITION

URINARY CALCIUM EXCRETION AND BLOOD CALCIUM LEVELS IN THE BOVINE NEAR THE TIME OF PARTURITION

Further Studies on the Influence of Dietary Calcium and Phosphorus on the Incidence of Milk Fever

Further Studies on the Influence of Dietary Calcium and Phosphorus on the Incidence of Milk Fever

The Influence of Dietary Calcium and Phosphorus on the Incidence of Milk Fever in Dairy Cattle

The Influence of Dietary Calcium and Phosphorus on the Incidence of Milk Fever in Dairy Cattle

Studies on Milk Fever in Dairy Cows. II. The Effect of Vitamin D on Some of the Blood Changes in Normal and Milk Fever Cows at Parturition

Many of the usual blood changes occurring at parturition and in milk fever have been extensively investigated. Since Little and Wright (24) reported low blood calcium values ill COWS with milk fever much attention has been given to various mineral constituents of the blood. It appears that when an explanation is found for the changes in the mineral constituents of the blood and a way to prevent those changes can be devised, the mystery Of the milk fever syndrome will be solved. Since the report of Little and Wright (24) numerous reports have been submitted dealing with total calcium (1, 2, 10, 11, 12, 14, 15, 17, 24, 25, 27. 32, 33, 36) and diffusible calcium (15, 27, 30, 33) in the blood of normal and milk fever cows at parturition. All are in agreement that a marked decrease in both total and diffusible calcium occurs in milk fever. A sharp drop in blood inorganic phosphorus in milk fever-has been repeatedly reported (2, 11, 14, 15, 27, 29, 30, 33, 36). In contrast to serum calcium and phosphorus, serum magnesium is said to increase during milk fever (1, 2, 15, 23, 29, 30, 31, 33). The work of Mattick and Little (26) suggests some benefit in preventing the fall of blood calcium and phosphorus at parturition as the result of feeding cod-liver oil. The present paper is a report of s~udies covering the effect of irradiated yeast feeding on some of the blood changes at parturition and in milk fever, made in connection with the experiment described in the preceding paper (20) involving the effect of feeding vitamin D in the form of irradiated dry yeast on the incidence of milk fever.

The Hannah Dairy Research Institute

A BRIEF account of the researches already carried out at the recently established Hannah Dairy Research Institute, Kirkhill, Ayr, is given by the director, Dr. N. C. Wright, in the Ayrshire Cattle Society's Journal, vol. 3, No. 1. An investigation into the incidence of certain bovine diseases, especially tuberculosis and milk fever, has been commenced, and, as a result, recommendations have been made which should lead to the elimination from tested herds of a large proportion of the animals reacting positively to the tuberculin test. Inquiry is also being made into the length of life of milking cows in Scottish herds and into the main causes which lead to the unremunerative disposal of stock. The problems of the utilisation of surplus milk and of milk by-products also received attention. Investigations on the biological side require laboratory accommodation, which has only recently become adequate with the completion of the buildings at Kirkhill. They will include a re-investigation of the protein requirements of dairy cows, and an investigation of the physiology of lactation. In addition, the problems involved in improvement of the dairy stock by selective inbreeding and in the methods used in condensing and drying milk, separated milk, and whey will be examined. Two-thirds of the income of the Institute is received in the form of a grant from the Development Commissioners, but the remaining third must be raised from non-government sources. It is estimated that £2000 will be required annually, and it is hoped to secure an endowment fund which will supply an assured income of this order.